This invention relates to an arrangement for connecting two or more heat exchangers with one another which are each equipped with collecting tanks, particularly made of plastic, and with flow paths with heat exchange surfaces for a heat exchange medium extending between these collecting tanks.
In practice, particularly in vehicle construction, it is often necessary to join several heat exchangers in order to, for example, in the case of a commercial vehicle, connect a charge air cooler with the radiator for the engine coolant. The mounting of such heat exchangers may result in high expenditures when, for example, in the case of narrow space conditions in the engine compartments of motor vehicles, one cooler or radiator is to be mounted to the cooler or radiator already situated in the vehicle.
Since the connections of the cooler and the radiator are to be designed such that they compensate the different heat expansions of the radiator and the cooler and must also absorb manufacturing tolerances, special holding devices and screwed connections have been provided so that the forces occurring as a result of the acceleration of the masses in the vehicle operation can be absorbed in a perfect manner. The mounting operation by means of such screwed connections results in high expenditures.
It is an object of the invention to provide an arrangement of the initially mentioned type by means of which two or several heat exchangers can be fixedly connected with one another in a simple manner without the occurrence of problems caused by different heat expansions of the two heat exchangers or by tolerance-caused dimensional deviations.
According to the invention, this object is achieved in that pins, which project at a distance from one another and approximately perpendicularly from its longitudinal direction, are assigned to one of the collecting tanks of a heat exchanger. These pins can be introduced into corresponding openings in shackle-type abutments on the assigned collecting tank of the other heat exchanger, and can be positioned in a defined end position by a swivelling about an abutment surface. Locking devices, particularly snap hooks, for securing the end position of the pins and of the two heat exchangers are assigned to the other two collecting tanks. By means of this development, high-expenditure connection elements, such as screws, holding devices, or the like, become superfluous. One heat exchanger can be prepositioned on the other heat exchanger by the introduction of its pins and, by means of the folding in against the other heat exchanger, can be brought into its end position and can be locked there.
It is true that it is known from European Patent Document EP 0 346 601 B1, for the purpose of fastening the lateral parts of a radiator for vehicle engines, to cause pins to engage in recesses of the lateral parts, which pins are fastened on the collecting tanks and act in the manner of hinges in order to permit a hinging of the lateral parts on the collecting tanks for the purpose of mounting. In the case of the arrangement of lateral parts, the mutual alignment of two heat exchangers which may also be subjected to different heat expansions is not important. There also, the swivelled-in position of the lateral parts is secured by wedges which must be pushed in separately. The device illustrated there has nothing in common with the connection of two or more heat exchangers.
In a further development of the idea of the invention, two snap brackets may be provided as a locking device which can each be swivelled elastically about an axis, which are each approximately assigned to the end area of a collecting tank and which are aligned perpendicularly with respect to one another by means of their swivel axes. In a further development of the invention, the cross-sections of at least one of the pins and of the opening of the abutment assigned to it may be adapted to one another in the longitudinal direction of the collecting tanks so that, after the pins were introduced into the assigned openings and during the swivelling, a precise alignment can also take place of the two water boxes in the direction of the longitudinal axis of their collecting tanks. This may be promoted by the fact that one of the pins has a rectangular cross-section but the other one has a square cross-section with two lateral walls which are aligned in parallel with respect to one another and in the case of which at least one additional lateral wall extends diagonally with respect to the wall opposite from it and, in its slope, corresponds to the slope of the wall of the abutment interacting with it during the positioning of the heat exchanger. By means of this development, one of the pins receives, on at least one side, a wedge-type construction which has the result that an alignment occurs in one direction during the swivel operation without the requirement of taking special measures for such an alignment. Since the sloping takes place only in one direction and on one lateral wall, it is nevertheless still possible for the pins to shift perpendicularly with respect to the longitudinal axes of the collecting tanks, should heat expansions occur.
In a further development of the invention, one of the snap brackets may be aligned horizontally and the other may be aligned perpendicularly, in which case one contact surface for a stop of a heat exchanger and one opposite surface as an engaging edge as well as elastic rib will then be assigned to each snap bracket which are assigned to the engaging edge in such a manner that its free end is situated in the moving path of the end of the snap bracket provided with the detent hook and, when the snap bracket is engaged, presses against the side of the end of the snap brackets which faces away from the detent hooks. On the one hand, because of the perpendicular arrangement of the snap brackets with respect to one another, this development ensures that also a parallelogram shape caused by manufacturing can be compensated; that is, a shape of the heat exchangers which deviates from a precise rectangle and which may in fact occur in practice as a result of manufacturing. The perpendicular snap bracket is arranged close to a fixed-bearing point and may carry out its function also in the case of angular deviations of the bottom.
Since, in the area of the horizontally arranged snap bracket, a sloped position of the bottom must also be expected, it is advantageous for the support surface of the horizontally aligned snap bracket to have a slightly elastic construction.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.